Screw piles are a form of footing or anchoring system used in the building or construction industry. They are typically in the form of a hollow shaft having a helical attachment welded to one end of the shaft. This end of the shaft is driven into the ground by rotational force, whereby the helical attachment cuts through the ground in a similar manner to a screw. Once the shaft reaches a desired depth in the ground, the helical attachment acts to secure the shaft with respect to the ground and also with respect to forces acting on the shaft. The attachment to the shaft may alternatively take the form of a combination of a single horizontal plate bolted to the shaft and a number of sharp, vertical plates extending from the horizontal plate. The sharp, vertical plates penetrate and engage the ground to secure the shaft.
Another known system for securing a pile or post in the ground is through the use of a concrete footing for the ground-engaging end of the pile or post. To create the concrete footing, a portion of the ground surrounding the pile is excavated and filled with concrete. Once the concrete sets, the pile or post is permanently secured in place.
One disadvantage of such known systems is that they may not be sufficient to counter high lateral forces acting on the pile, post or shaft, for example in severe weather situations where sustained strong winds can cause the pile, post or shaft to collapse. Further, such known systems are typically designed to have the pile or post permanently fixed to an attachment or concrete footing within the ground, thus making it difficult to remove the pile or post from the ground without the use of complex machinery. Therefore, such known systems do not have the capacity for the pile or post to easily be removed from one site, transported to another site and re-used.